This invention relates to a vending machine, and more particularly, to a temperature control mechanism for a vending machine.
Various types of automatic vending machines are known for dispensing different types of merchandise. Some types of merchandise, such as a can or bottle containing a beverage, are stored in the vending machine in refrigerated or heated conditions to promote the sales of the merchandise. Therefore, certain vending machines should be provided with refrigerating and heating mechanisms.
With reference to FIGS. 1 and 2, a vending machine having conventional refrigerating and heating mechanisms will be explained. Interior space of the vending machine 1 is viertically divided into two chambers, such as storage chamber 1a and mechanical chamber 1b. Storage chamber 1a contains a plurality of dispensing columns 2 in which merchandise is stored and a shut plate 3 disposed below the bottom portion of dispensing columns 2 and slanted to guide the merchandise to a discharge opening (not shown). A plurality of holes 3a are formed through shut plate 3 to allow forced air circulation within the storage chamber 1a. Refrigerating apparatus 4 includes evaporator 4a and heating device 5 which are disposed underneath shut plate 3. Blower fan 6 circulates refrigerated and heated air. Because shut plate 3 is oriented at a slant, the space for disposing some parts of refrigerating apparatus 4 such as heating device 5 is provided. Other components of refrigerating apparatus 4 are dispsed within mechanical chamber 1b.
The refrigerated or heated air is returned to the space underneath shut plate 3 through duct 7 after heat exchange with the stored merchandise. Duct 7 is formed on the rear side of storage chamber 1a, as clearly shown in FIG. 2. Upper opening 7a of duct 7 is positioned at about the vertical midpoint of column 2. Therefore, merchandise stored in the lower half portion of each column 2 is refrigerated or heated.
One of the drawbacks of such vending machines is the potential for merchandise to be dispensed at an undesirable temperature. This may occur when the dispensing rate increases due to increased demand. One solution to this disadvantage is to fully refrigerate each column. This may be accomplished by positioning upper opening 7a of duct 7 at the upper end portion of column 2. However, if the dispensing rate decreases due to a decreased demand, merchandise stored on the upper half space of column 2 may be over-cooled or overheated which may adversely effect its flavor or quality.